In active matrix-type liquid crystal display devices, display is controlled by supplying a data signal to each pixel electrode, thus applying across a liquid crystal layer a voltage between the pixel electrode and a common electrode. The data signal is generated as an AC signal that takes both positive and negative polarities, having a common voltage at the center. However, an amplitude of the data signal is limited by a restriction from a power-supply system and/or a restriction from power consumption. Therefore, the voltage applied to the liquid crystals does not always have a range wide enough to make it possible to achieve a sufficient contrast. Accordingly, liquid crystal display devices performing a capacitive coupling drive has been proposed. The capacitive coupling drive performs upthrusts and downthrusts of a pixel electrode potential by driving a storage capacitor line of each pixel. For example, Patent Literatures 1 to 3 disclose driving methods in each of which the capacitive coupling drive has been further improved.
In some cases, the storage capacitor line drive circuit includes a CS driver (storage capacitor line drive circuit) 104 disposed so that a pixel section 102 is provided between a gate driver (scanning signal line drive circuit) 103 and the CS driver 104, as shown in a liquid crystal display device 101 of (a) of FIG. 8. In other cases, the storage capacitor line drive circuit includes a CS driver (storage capacitor line drive circuit) combined with a gate driver (scanning signal line drive circuit) in a driver 113 disposed in a frame area on one side of an pixel section 112, as shown in a liquid crystal display device 111 of (b) of FIG. 8.
The disposition of the gate driver 103 and the CS driver 104 shown in (a) of FIG. 8 is in accord with narrowing of a frame. In this disposition, the CS driver 104 uses a scan signal in order to read a polarity identification signal FR, and this scan signal is inputted into the CS driver 104 via a gate bus line GL provided in an area of the pixel section 102 after being outputted from the gate driver 103. In contrast, the disposition of the gate driver and the CS driver shown in (b) of FIG. 8 is obtained by incorporating the CS driver into a conventional gate driver. In this disposition, the CS driver receives, from the gate driver within the driver 113, a scan signal that the CS driver uses for reading a polarity identification signal FR.